Its claim to fame: Studies have suggested a link between selenium intake and reduced risk of prostate, colon, and lung cancer. But so far none have been conclusive enough to warrant adding a supplement with this nutrient. In fact, if you live in the United States, chances are you're getting enough selenium in your diet. The reason: selenium is in the soil. Produce grown in selenium-rich soil will contain the mineral, says Dr. Raymond Burk, director of clinical nutrition research unit at Vanderbilt University.
Old RDA: 55 micrograms for women, 70 micrograms for men.
New RDA: 55 micrograms for all adults.
Recommended upper limit: 400 micrograms, for adults age 19 and up. This limit was set because too much selenium causes hair to fall out, and makes nails brittle.
Best food sources: Brazil nuts, seafood, meat, chicken, and whole-grain foods.
Continued on page 5: Carotenoids